Entoloma secotioides J. Garcia , Guevara & de la Fuente, 2023

de la Fuente, Javier Isaac, Garcia-Jimenez, Jesus, Raymundo, Tania, Sanchez-Flores, Marcos, Valenzuela, Ricardo, Guevara-Guerrero, Gonzalo, Perez-Ovando, Erika Cecilia & Martinez-Gonzalez, Cesar Ramiro, 2023, Elaphomyces castilloi (Elaphomycetaceae, Ascomycota) and Entoloma secotioides (Entolomataceae, Basidiomycota), two new sequestrate fungi from tropical montane cloud forest from south Mexico, MycoKeys 96, pp. 127-142 : 127

Entoloma secotioides J. Garcia, Guevara & de la Fuente sp. nov.

. Fig. 5A-F

Type material.

Holotype. Mexico. Chiapas: la Trinitaria Municipality, Lagunas de Monte bello, alt. 1004 m, 16°53'N, 93°27'W, 16 August 2019, J. García 18817 (Holotype-ITCV).

Diagnosis.

Entoloma secotioides is characterized by cream colored, sulcate, secotioid basidiomata, not anastomosed gills, and angular basidiospores (7-13 × 5-9 µm).

Etymology.

Named Entoloma secotioides due to the secotioid basidiomata.

Description.

Pileus 12-15 mm, subglobose, flattened when young, becoming depressed when mature, sulcate, pale yellow (4A3) to light yellow (4A5), slightly velvety, margin incurved enclosing the hymenium, dry in appearance, sometimes with brownish fibrils. Hymenophore lamellate, slightly irregular, pale orange to orange white (5A2) to light yellow (4A5), not exposed even in mature specimens. Stipe 4-9 × 3-4 mm, cylindrical or absent, light yellow (4A5), smooth or finely fibrillose. Taste and odor fungoid, mild.

Peridium 70-300 µm composed of loosely interwoven or horizontally arranged hyphae, 4-7 µm in diameter, septate, bifurcate, hyaline to pastel green in 5% KOH (27A4), not reacting with Melzer, with clavate terminal cells, thin-walled. Hymenophoral trama 45-110 µm in diameter, composed of interwoven compacted hyphae, 4-9 µm in diameter, light orange in 5% KOH (5A4), thin-walled. Basidia 27-35 × 5-10 µm forming palisades, clavate, hyaline, thin-walled, embedded by a layer of loosely interwoven hyphae which arise from the trama, 6-11 µm diameter, sometimes branched, inflate at the septum, sometimes with terminal cells cystidioid or cylindrical, thin-walled. Basidiospores 7-13 × 5-9 µm, (L = 10.2, W = 7.1, Q = 1-2.2, n = 30), angular, rare nodulose, with 6-8 sides, some with conspicuous hilar appendix up to 3 µm, hyaline to pastel green (27A4), not reacting with Melzer reagent, smooth, thin-walled.

Distribution.

Known only from the state of Chiapas, growing sub hypogeous under Quercus sp. and Pinus sp. in montane cloud forest.

Additional material studied.

Mexico. Chiapas: la Trinitaria Municipality, Lagunas de Monte bello, alt. 1004 m, 16°53'N, 93°27'W, 16 August 2019, Guevara 1173 (Paratype-ITCV). ITS: OP821421 ; LSU: OP824741 ; RPB2: KC265753 .

Notes.

Entoloma secotioides is characterized by pale-cream basidiomata, enclosed, not anastomosed gills, and angular basidiospores 7-13 × 5-9 µm. Entoloma calongei (E. Horak & G. Moreno) Noordel. & Co-David has gray-brown pileus, loculate gleba, and basidiospores 6-10 µm ( Horak and Moreno 1998); Entoloma chilensis (E. Horak) Noordel. & Co-David also has grayish pileus, loculate gleba, and basidiospores 9-11 × 6.5-7.5 µm ( Horak 1963). Both species differ from E. secotioides mainly in the basidiomata color (pale-cream vs. grayish-brown) and hymenophore shape (slightly irregular vs. locules). The new species is phylogenetically close to E. asterosporum (Coker & Couch) T.J. Baroni & Matheny, differing from E. secotioides by having the globose sporome, pungent odor and smell, and larger spores (up to 16 µm) ( Baroni and Matheny 2011).

Figures

Figure 5. Entoloma secotioides (Holotype) A, B basidiomata showing the pileus, hymenia, and stipe C peridium D, E details of the hymenium F basidiospores in KOH.